def _partition(array, lo, hi):
pivot = array[hi]
i = lo
for j in range(lo, hi + 1):
if array[j] < pivot:
swap(array, i, j)
i += 1
swap(array, i, hi)
return i
def insertion_sort(li):
sort_utils.swap_tracker_reset()
for i in range(len(li) - 1):
for j in range(i + 1, 0, -1):
value_before = j - 1
if li[j] < li[value_before]:
sort_utils.swap(li, j, value_before)
else:
break
return li
def selection_sort(li):
sort_utils.swap_tracker_reset()
for i in range(len(li) - 1):
index_smallest = i
for j in range(i + 1, len(li)):
if li[j] < li[index_smallest]:
index_smallest = j
if index_smallest != 0:
sort_utils.swap(li, index_smallest, i)
return li
def sort(array):
"""
Selection sort
Complexity
Memory
O(n) - since all swaps "in place"
and no addition data strictures requires
Time
Always O(n^2) - because no matter how array element is placed,
second pointer go till the end
"""
for i in range(len(array)):
j = i
while j > 0 and array[j - 1] > array[j]:
swap(array, j, j - 1)
j -= 1
def sort(array):
"""
Selection sort
Complexity
Memory
O(n) - since all swaps "in place"
and no addition data strictures requires
Time
Always O(n^2)
Inner loop always lookup for minimum element,
even when array is sorted
"""
for i in range(len(array)):
min_element = i
for j in range(i, len(array)):
if (array[j] < array[min_element]):
min_element = j
swap(array, i, min_element)
def sort(array):
"""
Bubble sort
Complexity
Memory
O(n) - use same array and swap "in place"
Time
Worst: O(n^2) - when array is reversed
((n - 1) + (n - 2) + ... + (n - n))/2 ~ O(n^2)
Average: O(n^2)
Best: ϴ(n) - when array is sorted
"""
is_sorted = False
while not is_sorted:
is_sorted = True
for i in range(len(array) - 1):
if array[i] > array[i + 1]:
is_sorted = False
swap(array, i, i + 1)
#!/usr/bin/env python3
import sort_utils
tests_passed = 0
total_tests = 0
test_name = "Test 1"
print(f"---- {test_name} ----------------------------")
orig = list("abcdef")
li = list(orig)
sort_utils.swap(li, 2, 3)
print(li)
print("----------------------------------------")
total_tests += 1
expected = list("abdcef")
if expected == li:
tests_passed += 1
else:
print(f"{test_name} failed.")
test_name = "Test 2"
print(f"---- {test_name} ----------------------------")
orig = list("abcdef")
li = list(orig)
sort_utils.swap(li, 0, 5)
sort_utils.swap(li, 1, 4)
sort_utils.swap(li, 2, 3)
print(li)
print("----------------------------------------")